Olefin-based thermoplastic elastomer compositions have been widely used in automobile interior parts, automobile exterior parts, electric parts, home electronics parts, furniture parts, footwear parts, and architectural parts.
In order to adapt to the required performance of each part, a composite molded body in which a molded body comprising a thermoplastic elastomer composition and a molded body comprising a material other than a thermoplastic elastomer composition are welded with each other is used in some cases as the part. Patent Document 1 describes a composite molded body in which a molded body comprising a thermoplastic elastomer composition containing a propylene-based polymer and an ethylene-propylene-based copolymer rubber and a molded body comprising a propylene-based polymer are welded with each other.